Overview
CVE-2025-65113 describes an authorization bypass vulnerability found in ClipBucket v5, a popular open-source video sharing platform. Prior to version 5.5.2 – #164, this flaw allows unauthenticated users to flag any content on the platform, including users, videos, photos, and collections. This can be exploited to launch mass flagging attacks, disrupt content availability, and abuse the moderation system.
Technical Details
The vulnerability resides in the AJAX flagging system. The application fails to properly verify user authentication before processing flagging requests. As a result, an attacker can craft malicious requests to flag content without needing to log in or authenticate. This bypasses the intended authorization controls, enabling unauthorized actions.
Example request:
POST /ajax.php?action=flag_item HTTP/1.1
Host: example.com
Content-Type: application/x-www-form-urlencoded
item_id=123&item_type=video&reason=inappropriate
Because authentication is not properly checked before processing this request, any user (or even an unauthenticated actor) could submit the request and successfully flag the video with `item_id=123`.
CVSS Analysis
- CVE ID: CVE-2025-65113
- Severity: MEDIUM
- CVSS Score: 6.5
The CVSS score of 6.5 indicates a medium severity vulnerability. While it doesn’t directly compromise the server or user data, the potential for large-scale content disruption and moderation system abuse makes it a significant risk. The lack of authentication required to exploit it contributes to the score.
Possible Impact
The exploitation of CVE-2025-65113 can lead to several negative consequences:
- Mass Flagging Attacks: Attackers can automatically flag large numbers of videos, photos, or users, leading to their removal or suspension.
- Content Disruption: Legitimate content can be flagged and removed, disrupting the platform’s functionality and user experience.
- Moderation System Abuse: The moderation team can be overwhelmed with false reports, hindering their ability to effectively manage the platform.
- Reputation Damage: The platform’s reputation can be damaged due to the prevalence of inappropriate content and the perceived lack of security.
Mitigation and Patch Steps
The vulnerability has been patched in ClipBucket v5.5.2 – #164. The recommended mitigation is to immediately upgrade to this version or a later version. The patch includes proper authentication checks in the AJAX flagging system to prevent unauthenticated users from submitting flagging requests.
To upgrade:
- Back up your ClipBucket database and files.
- Download the latest version of ClipBucket (v5.5.2 – #164 or later) from the official website.
- Follow the upgrade instructions provided in the ClipBucket documentation.
- Verify that the flagging system is now properly authenticated.
